Norm-Explicit Quantization: Improving Vector Quantization for Maximum Inner Product Search

Vector quantization (VQ) techniques are widely used in similarity search for data compression, fast metric computation and etc. Originally designed for Euclidean distance, existing VQ techniques (e.g., PQ, AQ) explicitly or implicitly minimize the quantization error. In this paper, we present a new angle to analyze the quantization error, which decomposes the quantization error into norm error and direction error. We show that quantization errors in norm have much higher influence on inner products than quantization errors in direction, and small quantization error does not necessarily lead to good performance in maximum inner product search (MIPS). Based on this observation, we propose norm-explicit quantization (NEQ) --- a general paradigm that improves existing VQ techniques for MIPS. NEQ quantizes the norms of items in a dataset explicitly to reduce errors in norm, which is crucial for MIPS. For the direction vectors, NEQ can simply reuse an existing VQ technique to quantize them without modification. We conducted extensive experiments on a variety of datasets and parameter configurations. The experimental results show that NEQ improves the performance of various VQ techniques for MIPS, including PQ, OPQ, RQ and AQ

Tai-Chi for Residential Patients with Schizophrenia on Movement Coordination, Negative Symptoms, and Functioning: A Pilot Randomized Controlled Trial

Objective. Patients with schizophrenia residing at institutions often suffer from negative symptoms, motor, and functional impairments more severe than their noninstitutionalized counterparts. Tai-chi emphasizes body relaxation, alertness, and movement coordination with benefits to balance, focus, and stress relief. This pilot study explored the efficacy of Tai-chi on movement coordination, negative symptoms, and functioning disabilities towards schizophrenia. Methods. A randomized waitlist control design was adopted, where participants were randomized to receive either the 6-week Tai-chi program and standard residential care or only the latter. 30 Chinese patients with schizophrenia were recruited from a rehabilitation residency. All were assessed on movement coordination, negative symptoms, and functional disabilities at baseline, following intervention and 6 weeks after intervention. Results. Tai-chi buffered from deteriorations in movement coordination and interpersonal functioning, the latter with sustained effectiveness 6 weeks after the class was ended. Controls showed marked deteriorations in those areas. The Tai-chi group also experienced fewer disruptions to life activities at the 6-week maintenance. There was no significant improvement in negative symptoms after Tai-chi. Conclusions. This study demonstrated encouraging benefits of Tai-chi in preventing deteriorations in movement coordination and interpersonal functioning for residential patients with schizophrenia. The ease of implementation facilitates promotion at institutional psychiatric services

Multiple Gene Polymorphisms in the Complement Factor H Gene Are Associated with Exudative Age-Related Macular Degeneration in Chinese

PURPOSE. Variants in the complement factor H (CFH) gene have been shown to be strongly associated with age-related macular degeneration (AMD). In this study, sequence alterations in CFH were investigated in 163 Chinese patients with exudative AMD and 155 unrelated Chinese control subjects. METHODS. All the 22 CFH exons, intron-exon boundaries, and promoter sequences were screened by polymerase chain reaction and DNA sequencing. RESULTS. Fifty-eight sequence changes, 42 of them novel, were identified. Six SNPs with an allele frequency Ͼ30% were significantly associated with exudative AMD. SNP rs3753396 was novel; the rest had been reported: rs3753394, rs551397, rs800292, rs2274700, and rs1329428. Two haplotype blocks were constructed. The TG haplotype for rs551397 and rs800292 was the major haplotype that conferred a significantly increased susceptibility to exudative AMD (P corr ϭ 0.0001, OR ϭ 1.91, 95% CI ϭ 1.36 -2.68). CONCLUSIONS. The findings support prior evidence that the CFH gene is one of the AMD-associated genes. There is a different distribution pattern of CFH variants in the Chinese compared with other populations. Individual SNP and haplotype analyses revealed that the ancient alleles at the 5Ј end of CFH contribute to an increased susceptibility to exudative AMD. (Invest Ophthalmol Vis Sci. 2008;49:3312-3317) DOI:10.1167/iovs.07-1517 A ge-related macular degeneration (AMD; MIM 603075; Mendelian Inheritance in Man) is a major cause of irreversible visual impairment and blindness in people older than 65 years in developed countries. 1,2 The occurrence of AMD is pan ethnic, and a high prevalence AMD has been reported in the elderly Chinese population. 5 Therefore, a greater understanding of the primary pathophysiology is needed to advance treatment and preventive measures. The etiology of AMD is complex and multifactorial, probably resulting from interactions between environmental and multigenetic factors. 6 Genetic association studies have revealed that single nucleotide polymorphisms (SNPs) in the complement factor H gene (CFH; MIM 134370; e.g., Tyr402His) are significantly associated with susceptibility to AMD. 25 A fine-scale linkage disequilibrium mapping of AMD in the CFH region detected a point location of a causal variant between exons 1 and 2 of CFH other than exon 9 for Tyr402His. MATERIALS AND METHODS Patients and Control Subjects 21 Also recruited and given complete ophthalmic examinations were 155 unrelated control subjects, 72 men and 83 women ranging in age at recruitment from 60 to 99 years (mean Ϯ SD, 73.1 Ϯ 6.5 years). They matched the patients by age and gender and had no sign of AMD or other eye diseases, except mild myopia or senile cataract. The study protocol was approved by the Ethics Committee on Human Research, the Chinese University of Hong Kong. All the procedures used conformed to the tenets of the Declaration of Helsinki. Informed consent was obtained from all study subjects after explanation of the nature of the study. Sample Collection, PCR Amplification, DNA Sequencing, and SNP Genotyping Venous blood was obtained from each study subject, and genomic DNA was extracted with a DNA blood kit (QIAamp; Qiagen, Hilden, Germany). The promoter sequence up to Ϫ867 upstream and all coding sequences of the CFH gene, including intron-exon boundaries, were screened for sequence alterations. Primers were generated based on the GenBank sequence of CFH (NM_000186.2; http://www.ncbi. nlm.nih.gov/Genbank; provided in the public domain by the National Center for Biotechnology Information, Bethesda, MD). PCR was performed on a thermal cycler (model 9700; Applied Biosystems, Inc. [ABI], Foster City, CA) with optimized protocols 27 Statistical Analysis Hardy-Weinberg equilibrium (HWE) for each polymorphism was tested by 2 test. Allele or genotype frequencies between cases and control subjects were compared by 2 analysis or the Fisher exact test. The odds ratios (ORs) of the alleles and haplotypes were estimated by 2 test (SPSS ver.15.0; SPSS Inc., Chicago, IL). Population attributable risk (PAR) of the risk genotype was calculated with the formula f(R Ϫ 1)/R, where f is the faction of cases with the risk genotype and R is the measure of OR 8 . A pair-wise linkage disequilibrium (LD, DЈ) estimation between polymorphisms with a minor allele frequency (MAF) Ͼ 1%, and EM-based haplotype association analysis were performed with Haploview (ver. 3.32, from http://www.broad.mit.edu/mpg/ haploview/ provided in the public domain by the Broad Institute, Massachusetts Institute of Technology, Cambridge, MA). For multiple comparison, probabilities were corrected by permutation test (iterations, 10,000). Statistical significance was defined as a corrected P (P corr ) Ͻ 0.05. RESULTS CFH Variants in the Study Subjects A total of 58 sequence variations were identified, all of which followed Hardy Weinberg Equilibrium Six of the seven common variants Six SNPs were identified in the promoter, all supported decreased susceptibility to AMD Haplotype Association Analysis LD analysis revealed extension of LD throughout the CFH gene. We included SNPs with MAF Ͼ 5% and two missense changes, rs1061170 (Tyr402His) and Val837Ile, in our haplotype association analysis. Two distinct haplotype blocks were detected The haplotypes H3 and H4, which were defined by all six AMD-associated SNPs, conferred significantly reduced or increased AMD susceptibility (H3: OR ϭ 0.56, 95% CI ϭ 0.39 -0.80; H4: OR ϭ 1.63, 95% CI ϭ 1.19 -2.23). When a G allele of rs1065489 (Asp936Glu) was included in these two haplotypes, the H5, which contained all the alleles in H3, remain significantly associated with the disease (P corr ϭ 0.0012). However, when a G allele or a T allele was added to the H4, the newly constructed H6 and H7 were no longer AMD associated (P corr ϭ 0.052 and 0.177, respectively). We constructed two-allele haplotypes by using rs800292 (Val62Ile) with the uncommon SNPs rs1061170 (Tyr402His) and Val837Ile, to investigate the effects of the minor variants. H10 and H11, containing a T allele of rs1061170 (Tyr402His), remained significantly associated with AMD. However, the haplotypes containing a C allele of rs1061170 DISCUSSION Although the pathogenesis of exudative AMD has not been definitively elucidated, studies in the past few years have revealed important information on its genetic basis. Polymorphisms in the CFH gene have been shown to be AMD associated in different ethnic groups, although there are obvious differences in the occurrence of disease-susceptible SNPs between Caucasian and Oriental populations. 26 mapped a point location for a causal variant between exons 1 and 2, which approximates block 1 in our present study, suggesting that the 5Ј region of the CFH (N-terminal of factor H) is commonly associated with AMD in both Chinese and Caucasians. We found haplotype block 2 spanning a region from exon 10 to intron 15 and containing SNP rs2274700 (Ala473Ala, exon 10), which have recently been shown to have a strong association with AMD in Caucasians and Japanese. Besides the haplotypes in the two haplotype blocks, the haplotypes defined by the six common SNPs (H3, H4) were also significantly associated with exudative AMD. However, when Asp936Glu (in exon 18) was included in the at-risk haplotype H4 for association analysis, the haplotypes H6 and H7, including a G or a T allele respectively, were no longer significantly associated with the disease (P corr Ͼ 0.05). Thus, Asp936Glu is less likely to be a risk factor for exudative AMD in Chinese individuals, indicating the C-terminal of the factor H contributes less than other parts of the polypeptide to the development of exudative AMD. This observation is consistent with the findings of Hageman et al

Disease Burden of Clostridium difficile Infections in Adults, Hong Kong, China, 2006-2014

Cross-sectional studies suggest an increasing trend in incidence and relatively low recurrence rates of Clostridium difficile infections in Asia than in Europe and North America. The temporal trend of C. difficile infection in Asia is not completely understood. We conducted a territory-wide population-based observational study to investigate the burden and clinical outcomes in Hong Kong, China, over a 9-year period. A total of 15,753 cases were identified, including 14,402 (91.4%) healthcare-associated cases and 817 (5.1%) community-associated cases. After adjustment for diagnostic test, we found that incidence increased from 15.41 cases/100,000 persons in 2006 to 36.31 cases/100,000 persons in 2014, an annual increase of 26%. This increase was associated with elderly patients, for whom incidence increased 3-fold over the period. Recurrence at 60 days increased from 5.7% in 2006 to 9.1% in 2014 (p<0.001). Our data suggest the need for further surveillance, especially in Asia, which contains ≈60% of the world’s population

Wild Type and Mutant 2009 Pandemic Influenza A (H1N1) Viruses Cause More Severe Disease and Higher Mortality in Pregnant BALB/c Mice

BACKGROUND: Pregnant women infected by the pandemic influenza A (H1N1) 2009 virus had more severe disease and higher mortality but its pathogenesis is still unclear. PRINCIPAL FINDINGS: We showed that higher mortality, more severe pneumonitis, higher pulmonary viral load, lower peripheral blood T lymphocytes and antibody responses, higher levels of proinflammatory cytokines and chemokines, and worse fetal development occurred in pregnant mice than non-pregnant controls infected by either wild type (clinical isolate) or mouse-adapted mutant virus with D222G substitution in hemagglutinin. These disease-associated changes and the lower respiratory tract involvement were worse in pregnant mice challenged by mutant virus. Though human placental origin JEG-3 cell line could be infected and proinflammatory cytokines or chemokines were elevated in amniotic fluid of some mice, no placental or fetal involvement by virus were detected by culture, real-time reverse transcription polymerase chain reaction or histopathological changes. Dual immunofluorescent staining of viral nucleoprotein and type II alveolar cell marker SP-C protein suggested that the majority of infected alveolar epithelial cells were type II pneumocytes. CONCLUSION: The adverse effect of this pandemic virus on maternal and fetal outcome is largely related to the severe pulmonary disease and the indirect effect of inflammatory cytokine spillover into the systemic circulation

Constitutively Nuclear FOXO3a Localization Predicts Poor Survival and Promotes Akt Phosphorylation in Breast Cancer

Background: The PI3K-Akt signal pathway plays a key role in tumorigenesis and the development of drug-resistance. Cytotoxic chemotherapy resistance is linked to limited therapeutic options and poor prognosis. Methodology/Principal Findings: Examination of FOXO3a and phosphorylated-Akt (P-Akt) expression in breast cancer tissue microarrays showed nuclear FOXO3a was associated with lymph node positivity (p = 0.052), poor prognosis (p = 0.014), and P-Akt expression in invasive ductal carcinoma. Using tamoxifen and doxorubicin-sensitive and -resistant breast cancer cell lines as models, we found that doxorubicin- but not tamoxifen-resistance is associated with nuclear accumulation of FOXO3a, consistent with the finding that sustained nuclear FOXO3a is associated with poor prognosis. We also established that doxorubicin treatment induces proliferation arrest and FOXO3a nuclear relocation in sensitive breast cancer cells. Induction of FOXO3a activity in doxorubicin-sensitive MCF-7 cells was sufficient to promote Akt phosphorylation and arrest cell proliferation. Conversely, knockdown of endogenous FOXO3a expression reduced PI3K/Akt activity. Using MDA-MB-231 cells, in which FOXO3a activity can be induced by 4-hydroxytamoxifen, we showed that FOXO3a induction up-regulates PI3K-Akt activity and enhanced doxorubicin resistance. However FOXO3a induction has little effect on cell proliferation, indicating that FOXO3a or its downstream activity is deregulated in the cytotoxic drug resistant breast cancer cells. Thus, our results suggest that sustained FOXO3a activation can enhance hyperactivation of the PI3K/Akt pathway. Conclusions/Significance: Together these data suggest that lymph node metastasis and poor survival in invasive ductal breast carcinoma are linked to an uncoupling of the Akt-FOXO3a signaling axis. In these breast cancers activated Akt fails to inactivate and re-localize FOXO3a to the cytoplasm, and nuclear-targeted FOXO3a does not induce cell death or cell cycle arrest. As such, sustained nuclear FOXO3a expression in breast cancer may culminate in cancer progression and the development of an aggressive phenotype similar to that observed in cytotoxic chemotherapy resistant breast cancer cell models. © 2010 Chen et al.published_or_final_versio

Clinical Forms of Chikungunya in Gabon, 2010

Chikungunya fever (CHIK) is a disease caused by a virus transmitted to humans by infected mosquitos. The virus is responsible for multiple outbreaks in tropical and temperate areas worldwide, and is now a global concern. Clinical and biological features of the disease are poorly described, especially in Africa, where the disease is neglected because it is considered benign. During a recent CHIK outbreak that occurred in southeast Gabon, we prospectively studied clinical and biological features of 270 virologically confirmed cases. Fever and arthralgias were the predominant symptoms. Furthermore, variable and distinct clinical pictures including pure febrile, pure arthralgic and unusual forms (neither fever nor arthralgias) were detected. No severe forms or deaths were reported. These findings suggest that, during CHIK epidemics, some patients may not have classical symptoms (fever and arthralgias). Local surveillance is needed to detect any changes in the pathogenicity of this virus

Oral abstracts 3: RA Treatment and outcomesO13. Validation of jadas in all subtypes of juvenile idiopathic arthritis in a clinical setting

Background: Juvenile Arthritis Disease Activity Score (JADAS) is a 4 variable composite disease activity (DA) score for JIA (including active 10, 27 or 71 joint count (AJC), physician global (PGA), parent/child global (PGE) and ESR). The validity of JADAS for all ILAR subtypes in the routine clinical setting is unknown. We investigated the construct validity of JADAS in the clinical setting in all subtypes of JIA through application to a prospective inception cohort of UK children presenting with new onset inflammatory arthritis. Methods: JADAS 10, 27 and 71 were determined for all children in the Childhood Arthritis Prospective Study (CAPS) with complete data available at baseline. Correlation of JADAS 10, 27 and 71 with single DA markers was determined for all subtypes. All correlations were calculated using Spearman's rank statistic. Results: 262/1238 visits had sufficient data for calculation of JADAS (1028 (83%) AJC, 744 (60%) PGA, 843 (68%) PGE and 459 (37%) ESR). Median age at disease onset was 6.0 years (IQR 2.6-10.4) and 64% were female. Correlation between JADAS 10, 27 and 71 approached 1 for all subtypes. Median JADAS 71 was 5.3 (IQR 2.2-10.1) with a significant difference between median JADAS scores between subtypes (p < 0.01). Correlation of JADAS 71 with each single marker of DA was moderate to high in the total cohort (see Table 1). Overall, correlation with AJC, PGA and PGE was moderate to high and correlation with ESR, limited JC, parental pain and CHAQ was low to moderate in the individual subtypes. Correlation coefficients in the extended oligoarticular, rheumatoid factor negative and enthesitis related subtypes were interpreted with caution in view of low numbers. Conclusions: This study adds to the body of evidence supporting the construct validity of JADAS. JADAS correlates with other measures of DA in all ILAR subtypes in the routine clinical setting. Given the high frequency of missing ESR data, it would be useful to assess the validity of JADAS without inclusion of the ESR. Disclosure statement: All authors have declared no conflicts of interest. Table 1Spearman's correlation between JADAS 71 and single markers DA by ILAR subtype ILAR Subtype Systemic onset JIA Persistent oligo JIA Extended oligo JIA Rheumatoid factor neg JIA Rheumatoid factor pos JIA Enthesitis related JIA Psoriatic JIA Undifferentiated JIA Unknown subtype Total cohort Number of children 23 111 12 57 7 9 19 7 17 262 AJC 0.54 0.67 0.53 0.75 0.53 0.34 0.59 0.81 0.37 0.59 PGA 0.63 0.69 0.25 0.73 0.14 0.05 0.50 0.83 0.56 0.64 PGE 0.51 0.68 0.83 0.61 0.41 0.69 0.71 0.9 0.48 0.61 ESR 0.28 0.31 0.35 0.4 0.6 0.85 0.43 0.7 0.5 0.53 Limited 71 JC 0.29 0.51 0.23 0.37 0.14 -0.12 0.4 0.81 0.45 0.41 Parental pain 0.23 0.62 0.03 0.57 0.41 0.69 0.7 0.79 0.42 0.53 Childhood health assessment questionnaire 0.25 0.57 -0.07 0.36 -0.47 0.84 0.37 0.8 0.66 0.4